Question

(2013·亳州模拟) 　　　 difficult and challenging the task may be, w

Answer 1

选B。考查状语从句和名词性从句。此处however引导让步状语从句, 构成句式“However+形容词/副词+正常语序+主句”; that引导一个同位语从句, 表示possibility的具体内容。